Abstract

This paper discusses the theoretical and experimental implications of changing the distribution of energy among the guided modes of an optical fiber. Particular emphasis is placed on optimizing the intensity of the evanescent field for near-infrared sensor applications. Both theoretical and experimental results show that, by the shifting of energy from low-to high-order modes, the evanescent field can be enhanced by as much as an order of magnitude. A second benefit of adjusting the mode distribution through mode scrambling is the generation of a stable mode distribution which is relatively insensitive to minor changes in the fiber-optic launch conditions. Therefore, mode scrambling can provide a more stable and more sensitive evanescent field sensor suitable for spectroscopic applications.

Evanescent field characteristics of eccentric core optical fiber for distributed sensing

Jianxia Liu and Libo Yuan
J. Opt. Soc. Am. A 31(3) 475-479 (2014)

Effective modes investigation of transmitted and reflective heterocore optical fiber surface plasmon resonance sensors

Zhexuan Zheng, Zhikun Wang, Hongyun Gao, Jiafu Wang, and Min Li
Appl. Opt. 58(25) 6975-6982 (2019)

Mode-independent attenuation in evanescent-field sensors

Harald Gnewuch and Hagen Renner
Appl. Opt. 34(9) 1473-1483 (1995)

Fiber-optic evanescent wave sensor with a segmented structure

Jun Lou, Hong-zhi Xu, Ben Xu, Jie Huang, Ben-chong Li, and Wei-min Shen
Appl. Opt. 53(19) 4200-4205 (2014)

Advantage of multi-mode sapphire optical fiber for evanescent-field SERS sensing

Hui Chen, Fei Tian, Jingmao Chi, Jiri Kanka, and Henry Du
Opt. Lett. 39(20) 5822-5825 (2014)